The following discussion of the background of the invention is intended to facilitate an understanding of the present invention. However, it should be appreciated that the discussion is not an acknowledgment or admission that any of the material referred to was published, known or part of the common general knowledge in any jurisdiction as at the priority date of the application.
Driving force members are commonly used in any situation where a rotational driving force needs to be transferred from one article to components of another article. In many cases, the two driving force members are configured such that the internal profile of one is matched to the external profile of the other. This match in profiles is often an identical match.
Recently, in the field of process and developer cartridges, driving force members included to transfer substantially coaxial rotational driving force from an image processing apparatus to the photosensitive drum, or like components, have been implemented in the form of a twisted projection to be received within a twisted recess. While the use of driving force members having twisted profiles have produced benefits in the form of the driving force member being self-centring and also assisting in preventing disengagement of the driving force members while a rotational driving force is being applied, it has also introduced further complications. For instance:                Existing driving force members not having a twisted profile can not be used with a driving force member having a twisted profile because the point of engagement between the two driving force members is insufficient to facilitate the transfer of the rotational driving force;        A driving force member having a twisted profile requires further precision tooling equipment such as specialised plastic injection moulding machinery, to meet the exacting tolerances the twisted profile sets; and        A driving force member in the form of a projection capable of engaging with a recess must be substantially as long as the recess is deep to enable full engagement.        
It is therefore an object of the present invention to create a driving force member that seeks to provide at least one of the advantages of a driving force member having a twisted profile while overcoming at least one of the disadvantages of a driving force member having a twisted profile and that can be used with driving force members having either a twisted recess or non-twisted recess profile.
It should be appreciated that while the following description will be made in relation to image processing equipment, it is not restricted to use and may be used in any circumstance where rotational driving force is required to be imparted from one component to another.